EmailGuard
Email validation API

Stop bad emails before they enter your funnel

Validate syntax, catch disposable inboxes, and classify relay and role addresses in a single request—so every signup, lead, and checkout starts clean.

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One GET returns every signal — scroll to see each check in action.

See the detection timeline

Signals per lookup

8+ characteristics

Disposable coverage

Curated data + live DNS

Integration

REST API with SDKs

Detection

Every signal in one response

EmailGuard runs RFC-aware syntax checks, normalization, and classification for roles, consumer domains, privacy relays, and disposable hosts—returned as structured JSON from GET /api/v1/emails/detect. Read the guides in our knowledge base for each field.

  1. Syntax validation

    RFC-aware parsing catches malformed addresses and invalid suffixes using IANA root zone and Public Suffix List data before they pollute your database.

    Finding:Invalid TLD. `.notreal` is not in the IANA list. Further checks are skipped when syntax fails.

    API response
    {

      "code": "SUCCESS",
      "message": "ok",
      "data": {
        "email": "[email protected]",
        "syntax_validation": false,
        "normalized": "[email protected]"
      }
    }

  2. Normalization

    Deduplicate signups by canonicalizing local parts, domains, and subaddressing variants.

    Finding:Plus-tag and dot variants collapse to one canonical Gmail address. Flag subaddressing for routing rules.

    API response
    {

      "code": "SUCCESS",
      "message": "ok",
      "data": {
        "email": "[email protected]",
        "syntax_validation": true,
        "normalized": "[email protected]",
        "subaddressing": true
      }
    }

  3. Role address detection

    Flag info@, support@, and other shared inboxes so sales and marketing lists stay personal.

    Finding:Local part matches a shared inbox prefix. Route to support queues, not personal outreach.

    API response
    {

      "code": "SUCCESS",
      "message": "ok",
      "data": {
        "email": "[email protected]",
        "syntax_validation": true,
        "role_address": true
      }
    }

  4. Public domain detection

    Identify consumer mail providers when B2B fit or lead scoring depends on corporate domains.

    Finding:Domain is a known freemail provider. Useful for ICP filters and enrichment workflows.

    API response
    {

      "code": "SUCCESS",
      "message": "ok",
      "data": {
        "email": "[email protected]",
        "syntax_validation": true,
        "public_domain": true
      }
    }

  5. Relay domain detection

    Identify Apple Hide My Email, Firefox Relay, and other forwarding providers that skew engagement metrics.

    Finding:Domain is a Proton Pass relay. Treat as masked identity, not a direct personal inbox.

    API response
    {

      "code": "SUCCESS",
      "message": "ok",
      "data": {
        "email": "[email protected]",
        "syntax_validation": true,
        "relay_domain": true,
        "relay_provider": "protonmail"
      }
    }

  6. Disposable detection

    Block throwaway inboxes with continuously updated domain intelligence and live DNS for domains that have not yet hit public blocklists.

    Finding:Domain classified as disposable. Block at signup before the address enters your CRM.

    API response
    {

      "code": "SUCCESS",
      "message": "ok",
      "data": {
        "email": "[email protected]",
        "syntax_validation": true,
        "disposable": true,
        "detection_source": "precomputed"
      }
    }

Email detection overview · API reference

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